The document provides details about the Tokyo Sky Tree project, including: - It is a 634m tall broadcasting tower and restaurant in Sumida, Tokyo, built over 4 years at a cost of $800 million. - The soil at the site is silt, so a reinforced concrete wall pile foundation was used, with knuckle walls and piles driven 35m into the ground, to withstand earthquakes up to magnitude 7.3. - Vibration control systems include two tuned mass dampers installed at 620m and 625m heights, as well as a core column with oil dampers above 375m, to suppress motions from wind.

1. CASE STUDY ON
TOKYO SKY TREE
Presented By
J. Sai Akhil
(13131A0140)

2. POINTS TO BE COVERED
• Details of project
• Introduction of structure
• Foundation details
• Design criteria
• Vibration control system
• Safety measures

3. DETAILS OF PROJECT
• Project name – Tokyo Sky Tree
• Location – Sumida, Tokyo
• Height of project – 634m (G+32)
• Purpose – Broadcasting tower, Restaurant
• Project duration – 4 years
• Project cost – $800 million
• Contractor – Obayashi Corp.

6. FOUNDATION DETAILS
• Type of soil at site is silt.
• Hence RC wall pile type foundation
is adopted to counter the earthquake
effects.
• Spikes like protuberances rise from
walls to hold soil firmly.
• This technique is called Knuckle
Walls.
• Piles are driven 35m into the ground.

7. • Pile of length 2.3m and diameter of 10cm were
adopted.
• SRC pile system is adopted to have the continuity
of steel member.
• Maximum load was 40,000kN during
pull-out test
• Aspect ratio is about 9.0.
• Top displacement is too large if foundation has
poor vertical rigidity

8. DESIGN CRITERIA
• Tower was designed to resist up to the earthquake magnitude of 7.3
• The wind speeds at height of 600m were measured using balloons.
• Winds are measured using ultrasonic wind gauge for two years.

9. VIBRATION CONTROL
SYSTEM
• Two methods are used – Tuned Mass Damper(TMD)
Core Column System
• To suppress the wind at top of tower 2 TMDs are
installed in the means of weights, springs, dampers
• TMD weighing 40 tons are installed at 620m height
and TMD weighing 20 tons are installed at 625m
height

10. • A core column was provided in the
center of structure.
• It is a cylindrical shaped column of
reinforced concrete.
• Diameter is 8 m and height of
column is 375 m
• Above this height oil dampers are
provided to suppress the motions.

11. SAFETY MEASURES
• Providing waterproof canvas to workers to protect from wind and
dizzying.
• 2 safety lines are implemented instead of one to all the workers.
• 100 m steel protective panels are setup over the railway just beneath
the tower.
• Building huge steel scaffolding in ground and placing in required
position using cranes.